By Katherine Shrader The Associated Press

WASHINGTON – Senators raised doubts about the legal rationale for the Bush administration’s eavesdropping program yesterday, forcing Attorney General Alberto Gonzales to provide a lengthy defense of the operations he called a vital “early warning system” for terrorists.

A handful of Republicans joined Democrats in raising questions about whether President Bush went too far in ordering the National Security Agency’s monitoring operations. The senators were particularly troubled by the administration’s argument that a 2001 congressional resolution approving use of military force covered the surveillance of some domestic communications.

“The president does not have a blank check,” said Judiciary Chairman Arlen Specter, R-Pa., who wants the administration to ask the secretive Foreign Intelligence Surveillance Court to review the program.

“You think you’re right, but there are a lot of people who think you’re wrong,” Specter told Gonzales. “What do you have to lose if you’re right?”

Gonzales didn’t respond to Specter’s proposal directly. “We are continually looking at ways that we can work with the FISA court in being more efficient and more effective,” said the former Texas judge.

Under Bush’s orders, the ultra-secret National Security Agency has been eavesdropping – without warrants – on international communications of people in the United States whose calls and e-mails may be linked to Muslim extremists.

During the committee hearing, Gonzales and the senators reached as far back as eavesdropping ordered by President Washington and delved into court decisions surrounding presidential powers and the 1978 Foreign Intelligence Surveillance Act.

Gonzales repeatedly defended the current program as lawful, reasonable and essential to national security. He said the president’s authority was strongest in a time of war, and he called the monitoring operations an “early warning system designed for the 21st century.” He said no changes in law were needed to accommodate the monitoring.

“To end the program now would be to afford our enemy dangerous and potential deadly new room for operation within our own borders,” he said.

Democrats pressed Gonzales for details about the program and other similar operations, almost all of which he would not provide. They asked Specter to file subpoenas for classified legal opinions on the subject.

“The president and the Justice Department have a constitutional duty to faithfully execute the laws,” said Vermont Sen. Patrick Leahy. “Nobody is above the law, not even the president of the United States.”

Leahy asked if the administration has authorized the opening of U.S. citizens’ mail. Throughout the hearing, Gonzales chose his words carefully. “We’re only focused on international communications where one part … is al-Qaida,” he said.